Add X86 TZCNT instruction and patterns to select it. Also added core-avx2 processor which is gcc's name for Haswell.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@141939 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/Target/X86/X86Subtarget.cpp b/lib/Target/X86/X86Subtarget.cpp
index c2f60be..7064dd0 100644
--- a/lib/Target/X86/X86Subtarget.cpp
+++ b/lib/Target/X86/X86Subtarget.cpp
@@ -290,6 +290,7 @@
   , HasRDRAND(false)
   , HasF16C(false)
   , HasLZCNT(false)
+  , HasBMI(false)
   , IsBTMemSlow(false)
   , IsUAMemFast(false)
   , HasVectorUAMem(false)